第 9 课 · 第 1 阶段: 基础
祈使句：Let's / Don't
初级Imperatives: Let's / Don't
构成与用法
Let's + 动词，Don't + 动词 — 提议或要求别人做某事
1.形式
祈使句以动词原形开头，没有主语（默认主语是 “you”）。否定式：Don't + 动词原形。
| 例句 | |
|---|---|
| 肯定式 | Sit down. · Close the door. · Wait for me. |
| 否定式 | Don't worry. · Don't touch that. |
| 用 be | Be careful. · Be quiet. · Don't be late. |
| 用 never | Never share your password. |
2.用法
| 用途 | 例句 |
|---|---|
| 说明、指路 | Turn left at the traffic lights. · Add a pinch of salt. |
| 请求、命令 | Turn off your phones, please. |
| 警告 | Watch out! · Mind the gap. · Don't run! |
| 邀请、建议 | Come in. · Have a seat. · Take an umbrella. |
| 祝愿 | Have a nice day! · Enjoy your meal! · Get well soon! |
3.让语气更礼貌
祈使句可能听起来很直接。要让语气缓和一些：
- 在句首或句末加 please：Please wait here. / Wait here, please.
- 简单、很快的小动作前加 just：Just sign here.
- 请人帮忙时改成疑问句：Could you open the window?（见“请求、提议和许可”一课）。
对陌生人、同事或上司，最好用 “Could you…?”，而不是祈使句——即使加了 please 也一样。
4.Let's：建议一起做某事
Let's + 动词原形（= let us）邀请别人和你一起做某事。否定式：Let's not + 动词原形。
Let's go for a walk.
我们去散散步吧。
Let's not argue about it.
我们别为这事吵了。
5.加 you 来强调
有时说话人会加上 you 来分配任务或加强语气：You wait here, I'll get the car. 如果语气不友好，听起来会像在发号施令。
6.常见错误
Not touch it!Don't touch it!
否定式用 don't。
Don't to open the door.Don't open the door.
don't 后面不加 to。
Don't be worry.Don't worry.
worry 是动词，不需要 be。
Be not late.Don't be late.
be 的否定式也用 don't。
Let's to go.Let's go.
let's 后面用不带 to 的原形。
例句
- Don't touch the oven. It's very hot!
- Let's go for a walk. It's a beautiful day.
- Don't forget to bring your passport tomorrow.
- Let's take a photo here!
